browser_use_tab

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

With no annotations, the description carries the full burden. It discloses a non-obvious stateful behavior: switching carries 'the network/console recorder and any intercept rules across,' and that subsequent page_*/net_*/page_tap_at calls act on the newly selected tab. Minor response/error behaviors are not covered, but the key behavioral traits are disclosed.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

Two dense but efficient sentences. The first front-loads the core action and its consequential state transfer; the second immediately clarifies the automatic-follow behavior and the targeted use cases. No filler or repetition.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

For a tool with no output schema and no annotations, the description covers the essential operating context: how to reference the target tab, what state carries over, what subsequent tools will act on, and when the switch is needed. The undocumented optional sessionId is a minor gap, and error behavior is not described, but the tool is simple enough that the description is largely sufficient.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema description coverage is 0%, so the description must compensate. It gives meaningful context for the required 'index' by linking it to 'browser_tabs', but the optional 'sessionId' parameter is left unexplained in both the schema and the description, leaving a partial gap.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

States the specific verb 'Switch' and the resource ('the session's DRIVEN tab'), with an explicit source for the index ('from browser_tabs'). The phrase 'page_*/net_*/page_tap_at then act on THAT tab' further disambiguates it from list-only or close-only sibling tools.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

Gives explicit use cases: 'go back to the opener, or to drive a tab that wasn't opened by the page.' It also clarifies when the tool is not needed by explaining that bfa already auto-follows page-opened tabs, giving a clear when-not-to-use signal.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.